Originally Posted by laperacfo
ECU tuning is usually a waste of time and money on NA cars. You will get more hp and tq with bolt ons.
That really depends.. maybe it's not so great on BMWs, but in the honda world, ecu tuning can make significant improvements in power. Most of that is because of good rom editing software (like Hondata), that can be purchased and tuned by anyone, instead of getting it from a shop who sends the ecu out to some obscure place, and waits for it to come back reprogrammed.
sadly, nothing like this exists for bmw's yet.